We fitted a linear model (estimated using OLS) to predict utterance_length with age (formula: utterance_length ~ age). The model explains a statistically significant and substantial proportion of variance (R2 = 0.98, F(1, 13) = 771.19, p < .001, adj. R2 = 0.98). The model's intercept, corresponding to age = 0, is at 1.70 (95% CI [1.26, 2.14], t(13) = 8.33, p < .001). Within this model:
- The effect of age is statistically significant and positive (beta = 0.52, 95% CI [0.48, 0.56], t(13) = 27.77, p < .001; Std. beta = 0.99, 95% CI [0.91, 1.07])
Standardized parameters were obtained by fitting the model on a standardized version of the dataset. 95% Confidence Intervals (CIs) and p-values were computed using the Wald approximation.